Misc Fixes

==========

-NOTIFICATION_WM_QUIT fixed on android (seems tha way this is reported changed in newer sdk)
-WIP implementation of APK Expansion APIs for publishing games larger than 50mb in Play Store
-Feaures in the new tutorials are all present in the sourcecode
-This (hopefully) should get rid of the animation list order getting corrupted
-Improved 3D Scene Importer (Skeletons, Animations and other stuff were not being merged). Anything missing?
-In code editor, the automatic syntax checker will only use file_exists() to check preload() else it might freeze the editor too much while typing if the preload is a big resource
-Fixed bugs in PolygonPathFinder, stil pending to do a node and a demo

core/resource.h

@@ -126,7 +126,7 @@ public:
 	void set_name(const String& p_name);
 	String get_name() const;
 
-	void set_path(const String& p_path);
+	void set_path(const String& p_path,bool p_take_over=false);
 	String get_path() const;
 
 	Ref<Resource> duplicate(bool p_subresources=false);